As Great Britain, France, Spain and other European nations competed for control of the New World and its wealth they all in varying ways came to rely on African labor to develop their overseas colonial possessions. Exploiting its proximity to plantations in the British colonies in North America and the West Indies, King Charles II of Spain issued the Edict of 1693 which stated that any male slave on an English plantation who escaped to Spanish Florida would be granted freedom provided he joined the Militia and became a Catholic. This edict became one of the New World’s earliest emancipation proclamations.
Source: Black Then | Fort Mose (Florida): An Escaped Slave’s Promise Land